Prof. Zhou Peiyuan (P.Y. Chou) was a celebrated scientist, educationalist and social activist well-known both at home and abroad. He was an outstanding leader in the Chinese science and technology community, a founder of modern mechanics in China, a fighter dedicated to world peace and an international envoy of peace and goodwill sent by the Chinese people as well as a people-to-people diplomat for the promotion of international exchange and cooperation in science and technology. Prof. Zhou Peiyuan (PY Chou) was a celebrated scientist, educationalist and social activist well-known both at home and abroad. He was an outstanding leader in the Chinese science and technology community, a founder of modern mechanics in China, a fighter dedicated to world peace and an international envoy of peace and goodwill sent by the Chinese people as well as a people-to-people diplomat for the promotion of international exchange and cooperation in science and technology.